Kara Semotiuk

Germline BRCA Mutations in a Large Clinic-Based Cohort of Patients With Pancreatic Adenocarcinoma

PURPOSE The main purpose of this study was to determine the prevalence of pathogenic BRCA1 and BRCA2 mutations in a consecutively ascertained clinic-based cohort of patients with pancreatic ductal adenocarcinoma and describe the clinical and family history characteristics. PATIENTS AND METHODS Unselected, consecutive, incident patients with pancreatic ductal adenocarcinoma were recruited at a single cancer center over a 2-year period. Participants provided blood for DNA analysis and cancer family history, and cancer treatment records were reviewed. DNA from all patients was analyzed by Sanger sequencing and multiplex ligation-dependent probe amplification for germline variants in BRCA1 and BRCA2. RESULTS Three hundred six patients were eligible for analysis. Pathogenic germline BRCA mutations were identified in 14 patients (4.6%; 95% CI, 2.2% to 6.9%), including 11 patients with a BRCA2 mutation and three patients with a BRCA1 mutation. Having a cancer family history that met genetic testing criteria of the National Comprehensive Cancer Network or the Ontario Ministry of Health and Long-Term Care or self-reporting as Ashkenazi Jewish was significantly associated with BRCA mutation carrier status (P=.02, P<.001, and P=.05, respectively). However, the majority of the BRCA mutation-positive patients did not actually meet these genetic testing criteria. CONCLUSION Pathogenic BRCA mutations were identified in 4.6% of a large cohort of clinic-based patients. Considering the implications for family members of BRCA carriers, and possibly tailored chemotherapeutic treatment of patients, our finding has implications for broader BRCA genetic testing for patients with pancreatic ductal adenocarcinoma.

Comparison of clinical schemas and morphologic features in predicting Lynch syndrome in mutation-positive patients with endometrial cancer encountered in the context of familial gastrointestinal cancer registries.

Endometrial cancer (EC) is the most common extraintestinal malignancy in Lynch syndrome (LS) and often is the sentinel malignancy, yet there is no consensus regarding LS‐EC detection algorithms. In this study, the authors determined the efficacy of family/personal history and tumor morphology in predicting LS in a cohort of patients with EC who had mutation‐proven LS.

The histomorphology of Lynch syndrome-associated ovarian carcinomas: toward a subtype-specific screening strategy.

Women with Lynch syndrome (LS) are at increased risk for the development of epithelial ovarian cancer (OC). Analogous to previous studies on BRCA1/2 mutation carriers, there is evidence to suggest a histotype-specific association in LS-associated OCs (LS-OC). Whereas the diagnosis of high-grade serous carcinoma is an indication for BRCA1/2 germline testing, in contrast, there are no screening guidelines in place for triaging OC patients for LS testing based on histotype. We performed a centralized pathology review of tumor subtype on 20 germline mutation-confirmed LS-OCs, on the basis of morphologic assessment of hematoxylin and eosin–stained slides, with confirmation by immunohistochemistry when necessary. Results from mismatch-repair immunohistochemistry (MMR-IHC) and microsatellite instability (MSI) phenotype status were documented, and detailed pedigrees were analyzed to determine whether previously proposed clinical criteria would have selected these patients for genetic testing. Review of pathology revealed all LS-OCs to be either pure endometrioid carcinoma (14 cases), mixed carcinoma with an endometrioid component (4 cases), or clear cell carcinoma (2 cases). No high-grade or low-grade serous carcinomas or mucinous carcinomas of intestinal type were identified. Tumor-infiltrating lymphocytes were prominent (≥40 per 10 high-powered fields) in 2 cases only. With the exception of 1 case, all tumors tested for MMR-IHC or MSI had an MMR-deficient phenotype. Within this cohort, 50%, 55%, 65%, and 85% of patients would have been selected for genetic workup by Amsterdam II, revised Bethesda Guidelines, SGO 10% to 25%, and SGO 5% to 10% criteria, respectively, with <60% of index or sentinel cases detected by any of these schemas. To further support a subtype-driven screening strategy, MMR-IHC reflex testing was performed on all consecutive non-serous OCs diagnosed at 1 academic hospital over a 2-year period; MMR deficiency was identified in 10/48 (21%) cases, all with endometrioid or clear cell histology. We conclude that there is a strong association between endometrioid and clear cell ovarian carcinomas and hereditary predisposition due to MMR gene mutation. These findings have implications for the role of tumor subtype in screening patients with OC for further genetic testing and support reflex MMR-IHC and/or MSI testing for newly diagnosed cases of endometrioid or clear cell ovarian carcinoma.

Patients with Lynch syndrome mismatch repair gene mutations are at higher risk for not only upper tract urothelial cancer but also bladder cancer.

BACKGROUND Lynch syndrome (LS), or hereditary nonpolyposis colorectal cancer, is caused by mutations in mismatch repair (MMR) genes. An increased risk for upper tract urothelial carcinoma (UTUC) has been described in this population; however, data regarding the risk for bladder cancer (BCa) are sparse. OBJECTIVE To assess the risk of BCa in MMR mutation carriers and suggest screening and management recommendations. DESIGN, SETTING, AND PARTICIPANTS Cancer data from 1980 to 2007 were obtained from the Familial Gastrointestinal Cancer Registry in Toronto for 321 persons with known MMR mutations: mutL homolog 1, colon cancer, nonpolyposis type 2 (E. coli) (MLH1); mutS homolog 2, colon cancer, nonpolyposis type 1 (E. coli) (MSH2); mutS homolog 6 (E. coli) (MSH6); and PMS2 postmeiotic segregation increased 2 (S. cerevisiae) (PMS2). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Standardized incidence ratios from the Ontario Cancer Registry, using the Surveillance Epidemiology and End Results public database, were used to compare cancer risk in patients with MMR mutations with the Canadian population. Microsatellite instability analysis and immunohistochemistry (IHC) of the MMR proteins were also performed and the results compared with matched sporadic bladder tumors. RESULTS AND LIMITATIONS Eleven of 177 patients with MSH2 mutations (6.21%, p<0.001 compared with the Canadian population) were found to have BCa, compared with 3 of 129 patients with MLH1 mutations (2.32%, p>0.05). Of these 11 tumors, 81.8% lacked expression of MSH2 on IHC, compared with the matched sporadic cases, which all displayed normal expression of MSH2 and MLH1. The incidence of UTUC among MSH2 carriers was 3.95% (p<0.001), and all tumors were found to be deficient in MSH2 expression on IHC. Mutations in the intron 5 splice site and exon 7 of the MSH2 gene increased the risk of urothelial cancer. Limitations include possible inflated risk estimates due to ascertainment bias. CONCLUSIONS LS patients with MSH2 mutations are at an increased risk for not only UTUC but also BCa and could be offered appropriate screening.

Development and validation of a brief screening instrument for psychosocial risk associated with genetic testing: a pan-Canadian cohort study

Objectives To develop a brief, reliable and valid instrument to screen psychosocial risk among those who are undergoing genetic testing for Adult-Onset Hereditary Disease (AOHD). Design A prospective two-phase cohort study. Setting 5 genetic testing centres for AOHD, such as cancer, Huntingtons disease or haemochromatosis, in ambulatory clinics of tertiary hospitals across Canada. Participants 141 individuals undergoing genetic testing were approached and consented to the instrument development phase of the study (Phase I). The Genetic Psychosocial Risk Instrument (GPRI) developed in Phase I was tested in Phase II for item refinement and validation. A separate cohort of 722 individuals consented to the study, 712 completed the baseline package and 463 completed all follow-up assessments. Most participants were female, at the mid-life stage. Individuals in advanced stages of the illness or with cognitive impairment or a language barrier were excluded. Interventions Phase I: GPRI items were generated from (1) a review of the literature, (2) input from genetic counsellors and (3) phase I participants. Phase II: further item refinement and validation were conducted with a second cohort of participants who completed the GPRI at baseline and were followed for psychological distress 1-month postgenetic testing results. Primary and secondary outcome measures GPRI, Hamilton Depression Rating Scale (HAM-D), Hamilton Anxiety Rating Scale (HAM-A), Brief Symptom Inventory (BSI) and Impact of Event Scale (IES). Results The final 20-item GPRI had a high reliability—Cronbachs α at 0.81. The construct validity was supported by high correlations between GPRI and BSI and IES. The predictive value was demonstrated by a receiver operating characteristic curve of 0.78 plotting GPRI against follow-up assessments using HAM-D and HAM-A. Conclusions With a cut-off score of 50, GPRI identified 84% of participants who displayed distress postgenetic testing results, supporting its potential usefulness in a clinical setting.

Moderators of cancer-related distress and worry after a pancreatic cancer genetic counseling and screening intervention.

Although the hereditary breast and ovarian cancer literature has demonstrated short‐term gains in psychological adjustment following genetic counseling, there has been limited research examining long‐term outcomes and moderators. Moreover, there has been minimal research into the psychological effects of this intervention in populations at high risk for pancreatic cancer. This study examines the long‐term effects of pancreatic cancer screening and genetic counseling on cancer‐related distress and cancer worry in a high‐risk population at 1‐year follow‐up. Additionally, this study explores potential moderators of the effectiveness of this intervention.

DNA Mismatch Repair Status Predicts Need for Future Colorectal Surgery for Metachronous Neoplasms in Young Individuals Undergoing Colorectal Cancer Resection.

BACKGROUND: The treatment of colorectal cancer in young patients involves both management of the incident cancer and consideration of the possibility of Lynch syndrome and the development of metachronous colorectal cancers. OBJECTIVE: This study aims to assess the prognostic role of DNA mismatch repair deficiency and extended colorectal resection for metachronous colorectal neoplasia risk in young patients with colorectal cancer. DESIGN, SETTING, AND PATIENTS: This is a retrospective review of 285 patients identified in our GI cancer registry with colorectal cancer diagnosed at 35 years or younger in the absence of polyposis. MAIN OUTCOME MEASURES: Using univariate and multivariate analysis, we assessed the prognostic role of mismatch repair deficiency and standard clinicopathologic characteristics, including the extent of resection, on the rate of developing metachronous colorectal neoplasia requiring resection. RESULTS: Mismatch repair deficiency was identified in biospecimens from 44% of patients and was significantly associated with an increased risk for metachronous colorectal neoplasia requiring resection (10-year cumulative risk, 13.5% ± 4.2%) compared with 56% of patients with mismatch repair-intact colorectal cancer (10-year cumulative risk, 5.8% ± 3.3%; p = 0.011). In multivariate analysis, mismatch repair deficiency was associated with a HR of 3.65 (95% CI, 1.44–9.21; p = 0.006) for metachronous colorectal neoplasia, whereas extended resection with ileorectal or ileosigmoid anastomosis significantly decreased the risk of metachronous colorectal neoplasia (HR, 0.21; 95% CI, 0.05–0.90; p = 0.036). LIMITATIONS: This study had a retrospective design, and, therefore, recommendations for colorectal cancer surgery and screening were not fully standardized. Quality of life after colorectal cancer surgery was not assessed. CONCLUSIONS: Young patients with colorectal cancer with molecular hallmarks of Lynch syndrome were at significantly higher risk for the development of subsequent colorectal neoplasia. This risk was significantly reduced in those who underwent extended resection compared with segmental resection.

A Novel and Rapid Method of Determining the Effect of Unclassified MLH1 Genetic Variants on Differential Allelic Expression

Germline mutations in mismatch repair genes predispose patients to Lynch Syndrome and the majority of these mutations have been detected in two key genes, MLH1 and MSH2. In particular, about a third of the missense variants identified in MLH1 are of unknown clinical significance. Using the PeakPicker software program, we have conducted a proof-of-principle study to investigate whether missense variants in MLH1 lead to allelic imbalances. Lymphocyte RNA extracted from patients harboring known MLH1 variants was used to quantify the ratio of variant to wild-type transcript, while patient lymphocyte DNA was used to establish baseline allelic expression levels. Our analysis indicated that the missense variants c.350C>T, c.793C>T, and c.1852_1853AA>GC, as well as the truncating variant c.1528C>T were all associated with significantly unbalanced allelic expression. However, the variants c.55A>T and c.2246T>C did not demonstrate an allelic imbalance. These results illustrate a novel and efficient method to investigate the pathogenicity of unclassified genetic variants discovered in mismatch repair genes, as well as genes implicated in other inherited diseases. In addition, the PeakPicker methodology has the potential to be applied in the diagnostic setting, which, in conjunction with results from other assays, will help increase both the accuracy and efficiency of genetic testing of colorectal cancer, as well as other inherited diseases.

Lynch Syndrome Limbo: Patient Understanding of Variants of Uncertain Significance

Providers and patients encounter challenges related to the management of Variants of Unknown Significance (VUS). A VUS introduces new counseling dilemmas for the understanding and psychosocial impact of uncertain genetic test results. This descriptive study uses Mishel’s theory of uncertainty in illness to explore the experience of individuals who have received a VUS as part of the genetic testing process. Semi-structured interviews were conducted with 27 adult individuals who received a VUS for Lynch syndrome mismatch repair genes between 2002 and 2013. The interviews were transcribed and analyzed. Most individuals recalled their result and perceived various types of uncertainty associated with their VUS. Half of the participants appraised their variant as a danger and implemented coping strategies to reduce the threat of developing cancer. Mobilizing strategies to reduce their risk included vigilant cancer surveillance, information seeking and notifying relatives. The majority of participants were unaware of the possibility of a VUS before receiving their result and expected reclassification over time. These results provide insight into the ways healthcare providers can support patients who receive VUS for Lynch syndrome. Findings also provide direction for future work that can further explicate the impact of receiving a VUS.

Long-term psychosocial and behavioral adjustment in individuals receiving genetic test results in Lynch syndrome.

A cross‐sectional study of 155 participants who underwent genetic testing for Lynch syndrome (LS) examined long‐term psychosocial and behavioral outcomes. Participants completed standardized measures of perceived risk, psychosocial functioning, knowledge, and a questionnaire of screening activities. Participants were on average 47.3 years and had undergone testing a mean of 5.5 years prior. Eighty four (54%) tested positive for a LS mutation and 71 (46%) negative. For unaffected carriers, perceived lifetime risk of colorectal cancer was 68%, and surprisingly, 40% among those testing negative. Most individuals demonstrated normative levels of psychosocial functioning. However, 25% of those testing negative had moderate depressive symptoms, as measured by the Center for Epidemiologic Studies for Depression Scale, and 31% elevated state anxiety on the State‐Trait Anxiety Inventory. Being female and a stronger escape – avoidant coping style were predictive of depressive symptoms. For state anxiety, similar patterns were observed. Quality of life and social support were significantly associated with lower anxiety. Carriers maintained higher knowledge compared to those testing negative, and were more engaged in screening. In summary, most individuals adapt to genetic test results over the long term and continue to engage in screening. A subgroup, including some non‐carriers, may require added psychosocial support.